Engineer bifunctional antibacterial enzymes for treatment of S. aureus infections

设计双功能抗菌酶来治疗金黄色葡萄球菌感染

• 批准号: 9301389
• 负责人: Karl E Griswold
• 金额: $ 16.2万
• 依托单位: DARTMOUTH COLLEGE
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-20 至 2019-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9301389
• 关键词: Address; Algorithms; Anti-Bacterial Agents; Antibiotic Resistance; Antibiotics; Antibodies; Antigen-Antibody Complex; Bacteria; Bacterial Infections; Bacteriophages; Binding; Biological Response Modifier Therapy; Bispecific Antibodies; Blood; Blood Circulation; Catalytic Domain; Cause of Death; Cell Wall; Centers for Disease Control and Prevention (U.S.); Cessation of life; Chimera organism; Chimeric Proteins; Clinic; Clinical; Communities; Cytolysis; Dangerousness; Development; Dose; Drug Costs; Drug resistance; Drug-sensitive; Economics; Endopeptidases; Engineering; Enzymes; Exhibits; Eye Infections; Fc Immunoglobulins; Fc domain; Filtration; Frequencies; Genes; Genus staphylococcus; Half-Life; Healthcare Systems; Hospitalization; Hospitals; Human; Hydrolase; Immune response; Immunoglobulin G; Immunologic Surveillance; In Vitro; Incidence; Infection; Kidney; Lung; Lysostaphin; LytA enzyme; Medical; Methicillin Resistance; Molecular; Multi-Drug Resistance; Mutation; Patients; Peptidoglycan; Performance; Phenotype; Prophages; Protein Engineering; Proteins; Radial; Recombinants; Recording of previous events; Recycling; Resistance; Resistance development; Risk; Skin; Staphylococcus aureus; Stream; T-Lymphocyte Epitopes; Technology; Testing; Therapeutic; Toxic effect; Treatment outcome; Ursidae Family; Variant; antibody engineering; bacterial resistance; bactericide; bacteriocin; base; chemotherapy; clinical translation; combat; cost; dalton; design and construction; drug development; drug discovery; drug resistant bacteria; endolysin; enzyme therapy; experience; glomerular filtration; immunogenic; immunogenicity; improved; innovation; killings; lysin; methicillin resistant Staphylococcus aureus; neonatal Fc receptor; next generation; nonhuman primate; pathogen; resistant strain; scaffold; small molecule; synergism; therapeutic candidate

Abstract: Antibiotic resistance complicates the majority of Staphylococcus aureus (S. aureus) infections. A full two thirds of hospital-associated S. aureus infections and ~50% of those acquired in the community are now methicillin-resistant (MRSA). MRSA causes >450,000 infections in the US each year, and it is responsible for half of all deaths caused by drug-resistant bacteria. The high incidence of multi-drug resistance in S. aureus and other bacteria underscores the need for next-generation antibiotics capable of combating these dangerous pathogens. An increasingly compelling therapeutic strategy leverages recombinant enzymes, such as Staphylococcus simulans lysostaphin (LST), which degrade cell wall peptidoglycan causing bacterial lysis and death. LST is a highly potent anti-staphylococcal agent with proven efficacy against both drug-sensitive and drug-resistant strains of S. aureus. While LST holds great potential for combatting dangerous S. aureus infections, its utility as a systemically administered treatment is constrained by specific limitations. First, as a small protein of 26,942 daltons, LST is rapidly cleared from the blood stream by renal filtration. In the clinic, this fact might necessitate frequent, high dosing to achieve complete bacterial clearance. Providing the option to use lower doses and less frequent administration would reduce costs, ease patient burden, and improve treatment outcomes. Second, LST is subject to development of S. aureus resistance by virtue of mutations in the femA gene, which alters the specific peptidoglycan bond targeted by the enzyme. Synergistic 2-agent treatments have been shown to mitigate the risk of LST resistance. We propose here to construct a modular bifunctional lysin platform based on fusions with immunoglobulin Fc domains. The Fc domain is a natural bivalent display scaffold, and we aim to leverage validated knob and hole bispecific Fc engineering strategies to create heterobifunctional Fc-lysin chimeras. Specifically, we will fuse the LST catalytic and cell wall binding domains to one chain of a heterodimeric knob and hole Fc, and we will fuse the SA2 prophage endopeptidase domain to the second chain. The heterologous pairing of the two Fc chains will create a single molecular entity that integrates two complementary cell wall hydrolases known to exert anti-S. aureus synergy. The bifunctional Fc-lysin's two pronged attack on S. aureus cell walls should minimize acquired resistance. Additionally, the Fc domain will serve to extend the bifunctional lysin's circulation half-life by (i) increasing the molecule's size beyond the limit for first-pass glomerular filtration in the kidney, and (ii) engaging the neonatal Fc receptor (FcRn), which actively recycles IgG antibodies and promotes their exceptionally long half-lives. As a whole, this project seeks to develop a modular platform for engineering high performance antibacterial enzymes that capitalize on intramolecular synergy to kill drug-resistant bacterial pathogens.

翻译后摘要：抗生素耐药性复杂的大多数金黄色葡萄球菌（S。金黄色葡萄球菌）感染。全 三分之二的医院相关S.金黄色葡萄球菌感染，目前社区中约50%的感染者 耐甲氧西林（MRSA）。MRSA每年在美国造成超过450，000例感染， 一半的死亡是由抗药性细菌引起的。S.金黄色 和其他细菌的感染，强调了对下一代抗生素的需求， 病原体越来越引人注目的治疗策略利用重组酶，如 模拟葡萄球菌溶葡萄球菌酶（LST），其降解细胞壁肽聚糖，引起细菌裂解， 死亡LST是一种高效的抗葡萄球菌药物，对药物敏感和 S.金黄色。虽然LST在对抗危险的S.金黄色 然而，由于其在感染中的作用，其作为全身施用治疗的效用受到特定限制的约束。一是作为 LST是一种分子量为26，942道尔顿的小蛋白质，通过肾过滤从血流中迅速清除。在诊所，这 事实上，可能需要频繁的高剂量以实现完全的细菌清除。提供以下选项 使用较低剂量和较低频率的给药将降低成本，减轻患者负担，并改善 治疗结果。第二，LST受制于S的发展。金黄色葡萄球菌耐药性的突变， femA基因，它改变了酶靶向的特定肽聚糖键。协同2-agent 治疗已经显示出减轻LST抗性的风险。我们建议在这里建立一个模块化的 基于与免疫球蛋白Fc结构域融合的双功能溶素平台。Fc结构域是天然的 二价展示支架，我们的目标是利用经验证的结和孔双特异性Fc工程化策略 以产生异型双功能Fc-溶素嵌合体。具体来说，我们将融合LST催化和细胞壁结合 结构域的一条链的异源二聚体的球和洞Fc，我们将融合的pH 4SA 2原噬菌体内肽酶 域到第二链。两条Fc链的异源配对将产生单个分子实体 它整合了两种互补的细胞壁水解酶，已知可以发挥抗S。金黄色协同作用。双功能 Fc-lysin对S.金黄色葡萄球菌的细胞壁应使获得性抗性最小化。此外，Fc 结构域将通过（i）增加分子的大小， 超过肾脏中首过肾小球滤过的限制，和（ii）与新生儿Fc受体结合 （FcRn），其积极地使IgG抗体活化并促进其特别长的半衰期。总体而言，这 该项目旨在开发一个模块化平台，用于工程化高性能抗菌酶， 利用分子内协同作用杀死耐药细菌病原体。